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Antiferromagnetic spintronics1,2 shows great potential for high-density and ultrafast information devices. Magnetic tunnel junctions (MTJs), a key spintronic memory component that are typically formed from ferromagnetic materials, have seen rapid developments very recently using antiferromagnetic materials3,4. Here we demonstrate a twisting strategy for constructing all-antiferromagnetic tunnel junctions down to the atomic limit. By twisting two bilayers of CrSBr, a 2D antiferromagnet (AFM), a more than 700% nonvolatile tunnelling magnetoresistance (TMR) ratio is shown at zero field (ZF) with the entire twisted stack acting as the tunnel barrier. This is determined by twisting two CrSBr monolayers for which the TMR is shown to be derived from accumulative coherent tunnelling across the individual CrSBr monolayers. The dependence of the TMR on the twist angle is calculated from the electron-parallel momentum-dependent decay across the twisted monolayers. This is in excellent agreement with our experiments that consider twist angles that vary from 0° to 90°. Moreover, we also find that the temperature dependence of the TMR is, surprisingly, much weaker for the twisted as compared with the untwisted junctions, making the twisted junctions even more attractive for applications. Our work shows that it is possible to push nonvolatile magnetic information storage to the atomically thin limit.
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We report a new design of polymer phenylacetylene (PA) ligands and the ligand exchange methodology for colloidal noble metal nanoparticles (NPs). PA-terminated poly(ethylene glycol) (PEG) can bind to metal NPs through acetylide (M-C≡C-R) that affords a high grafting density. The ligand-metal interaction can be switched between σ bonding and extended π backbonding by changing grafting conditions. The σ bonding of PEG-PA with NPs is strong and it can compete with other capping ligands including thiols, while the π backbonding is much weaker. The σ bonding is also demonstrated to improve the catalytic performance of Pd for ethanol oxidation and prevent surface absorption of the reaction intermediates. Those unique binding characteristics will enrich the toolbox in the control of colloidal surface chemistry and their applications using polymer ligands.
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The unprecedented navigation ability in micro/nanoscale and tailored functionality tunes micro/nanomotors as new target drug delivery systems, open up new horizons for biomedical applications. Herein, we designed a light-driven rGO/Cu2 + 1O tubular nanomotor for active targeting of cancer cells as a drug delivery system. The propulsion performance is greatly enhanced in real cell media (5% glucose cells isotonic solution), attributing to the introduction of oxygen vacancy and reduced graphene oxide (rGO) layer for separating photo-induced electron-hole pairs. The motion speed and direction can be readily modulated. Meanwhile, doxorubicin (DOX) can be loaded quickly on the rGO layer because of π-π bonding effect. The Cu2 + 1O matrix in the tiny robots not only serves as a photocatalyst to generate a chemical concentration gradient as the driving force but also acts as a nanomedicine to kill cancer cells as well. The strong propulsion of light-driven rGO/Cu2 + 1O nanomotors coupled with tiny size endow them with active transmembrane transport, assisting DOX and Cu2 + 1O breaking through the barrier of the cell membrane. Compared with non-powered nanocarrier and free DOX, light-propelled rGO/Cu2 + 1O nanomotors exhibit greater transmembrane transport efficiency and significant therapeutic efficacy. This proof-of-concept nanomotor design presents an innovative approach against tumor, enlarging the list of biomedical applications of light-driven micro/nanomotors to the superficial tissue treatment.
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Cobre , Doxorrubicina , Grafito , Luz , Cobre/química , Humanos , Doxorrubicina/farmacología , Doxorrubicina/química , Grafito/química , Sistemas de Liberación de Medicamentos , Portadores de Fármacos/química , Portadores de Fármacos/efectos de la radiación , Supervivencia Celular/efectos de los fármacos , Liberación de Fármacos , Antibióticos Antineoplásicos/farmacología , Antibióticos Antineoplásicos/química , Línea Celular TumoralRESUMEN
Genetic variants related to colorectal adenoma may help identify those who are at highest risk of colorectal cancer development or illuminate potential chemopreventive strategies. The purpose of this genome-wide association study was to identify genetic variants that are associated with risk of developing a metachronous colorectal adenoma among 1,215 study participants of European descent from the Selenium Trial. Associations of variants were assessed with logistic regression analyses and validated in an independent case-control study population of 1,491 participants from the Colorectal Cancer Study of Austria (CORSA). No statistically significant genome-wide associations between any variant and metachronous adenoma were identified after correction for multiple comparisons. However, an intron variant of FAT3 gene, rs61901554, showed a suggestive association (P = 1.10 × 10-6) and was associated with advanced adenomas in CORSA (P = 0.04). Two intronic variants, rs12728998 and rs6699944 in NLRP3 were also observed to have suggestive associations with metachronous lesions (P = 2.00 × 10-6) in the Selenium Trial and were associated with advanced adenoma in CORSA (P = 0.03). Our results provide new areas of investigation for the genetic basis of the development of metachronous colorectal adenoma and support a role for FAT3 involvement in the Wnt/ß-catenin pathway leading to colorectal neoplasia.Trial Registration number: NCT00078897 (ClinicalTrials.gov).
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Adenoma , Neoplasias Colorrectales , Selenio , Humanos , Estudio de Asociación del Genoma Completo , Estudios de Casos y Controles , Adenoma/genética , Adenoma/prevención & control , Neoplasias Colorrectales/patología , Factores de Riesgo , ColonoscopíaRESUMEN
As a common vector-borne disease, dengue fever remains challenging to predict due to large variations in epidemic size across seasons driven by a number of factors including population susceptibility, mosquito density, meteorological conditions, geographical factors, and human mobility. An ensemble forecast system for dengue fever is first proposed that addresses the difficulty of predicting outbreaks with drastically different scales. The ensemble forecast system based on a susceptible-infected-recovered (SIR) type of compartmental model coupled with a data assimilation method called the ensemble adjusted Kalman filter (EAKF) is constructed to generate real-time forecasts of dengue fever spread dynamics. The model was informed by meteorological and mosquito density information to depict the transmission of dengue virus among human and mosquito populations, and generate predictions. To account for the dramatic variations of outbreak size in different seasons, the effective population size parameter that is sequentially updated to adjust the predicted outbreak scale is introduced into the model. Before optimizing the transmission model, we update the effective population size using the most recent observations and historical records so that the predicted outbreak size is dynamically adjusted. In the retrospective forecast of dengue outbreaks in Guangzhou, China during the 2011-2017 seasons, the proposed forecast model generates accurate projections of peak timing, peak intensity, and total incidence, outperforming a generalized additive model approach. The ensemble forecast system can be operated in real-time and inform control planning to reduce the burden of dengue fever.
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Culicidae , Dengue , Animales , China/epidemiología , Brotes de Enfermedades , Humanos , Mosquitos Vectores , Estudios RetrospectivosRESUMEN
This study introduces a new wearable fiber-optic sensor glove. The glove utilizes a flexible material, polydimethylsiloxane (PDMS), and a silicone tube to encapsulate fiber Bragg gratings (FBGs). It is employed to enable the self-perception of hand posture, gesture recognition, and the prediction of grasping objects. The investigation employs the Support Vector Machine (SVM) approach for predicting grasping objects. The proposed fiber-optic sensor glove can concurrently monitor the motion of 14 hand joints comprising 5 metacarpophalangeal joints (MCP), 5 proximal interphalangeal joints (PIP), and 4 distal interphalangeal joints (DIP). To expand the measurement range of the sensors, a sinusoidal layout incorporates the FBG array into the glove. The experimental results indicate that the wearable sensing glove can track finger flexion within a range of 0° to 100°, with a modest minimum measurement error (Error) of 0.176° and a minimum standard deviation (SD) of 0.685°. Notably, the glove accurately detects hand gestures in real-time and even forecasts grasping actions. The fiber-optic smart glove technology proposed herein holds promising potential for industrial applications, including object grasping, 3D displays via virtual reality, and human-computer interaction.
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Dedos , Articulaciones , Humanos , Rango del Movimiento Articular , Tecnología de Fibra Óptica , PosturaRESUMEN
BACKGROUND: Enhanced recovery after surgery (ERAS) has been proven to decrease the amount of opioid use and reduce postoperative pain for a variety of surgeries, including breast reconstruction. However, data on ERAS in breast augmentation is lacking. OBJECTIVES: This study aims to investigate the effectiveness and safety of ERAS for breast augmentation. METHODS: A standardized ERAS protocol was established with full consideration of all aspects of perioperative care. Patients undergoing implant-based breast augmentation were prospectively recruited between December 2020 and January 2023, and assigned to either the ERAS or non-ERAS group randomly. The primary outcome was the activity of daily living after surgery. The secondary was postoperative pain and other outcomes included time to freely elevation, vomiting frequency, the use of analgesics, and complications. RESULTS: A total of 122 patients were included, with 70 in the ERAS group and 52 in the non-ERAS group. Compared to non-ERAS patients, ERAS patients had a shorter time to freely elevation of upper limbs (2.3 d vs. 5.5 d, P < 0.001). For ERAS patients, the pain scores were significantly lower on postoperative days 1 to 3, the activity of daily living index was significantly higher on postoperative days 1 to 3 and the opioids consumption was decreased (7.1 mg vs. 46.2 mg, P = 0.018). No difference was observed in complication and hospital costs between the two groups. CONCLUSION: The ERAS protocol significantly reduced postoperative pain and the use of opioids and promoted a return to daily activities without increasing complications in breast augmentation. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .
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Recuperación Mejorada Después de la Cirugía , Mamoplastia , Humanos , Tiempo de Internación , Mamoplastia/efectos adversos , Mamoplastia/métodos , Dolor Postoperatorio/prevención & control , Atención Perioperativa , Estudios Prospectivos , Estudios Retrospectivos , FemeninoRESUMEN
BACKGROUND: New tumor biomarkers are needed to improve the management of colon cancer (CC), the second leading cause of cancer-related deaths in the United States. Carcinoembryonic Antigen (CEA), the translated protein of carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) gene, is used as a biomarker for CC. Cartilage Oligomeric Matrix Protein (COMP) is overexpressed in CC compared to normal colon tissues. This study aims to evaluate the expression of COMP by disease stage, consensus molecular subtype (CMS), its impact on disease outcomes, and comparison to CEACAM5. MATERIALS AND METHODS: RNA-seq data from 456 CC The Cancer Genome Atlas samples and 41 matching control samples were analyzed for COMP expression and CEACAM5 expression. We stratified tumor samples by stage (I-IV), subtype (CMS1-CMS4), tumor location, and Kirsten RAt Sarcoma (KRAS) mutant status and three quartiles were established based on COMP expression. Kaplan Meier survival outcomes were evaluated. RESULTS: COMP expression was significantly higher in tumor samples, with elevation of expression occurring in stage I and significantly increasing in stage IV. Increased COMP expression occurs in CMS4 with relatively low expression in CMS3. No significant expression difference was attributed to tumor location and KRAS mutant status. Compared to CEACAM5, COMP was a stronger molecular marker across stages and subtypes. CMS4 was associated with the high COMP expression, and higher levels of COMP were associated with poorer overall survival, disease-specific survival, and tumor progression-free intervals. CMS2 and 3 were associated with low expression and better survival. CONCLUSION: COMP is a potential molecular biomarker for CC and may be superior to CEA as an indicator of CC.
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Neoplasias del Colon , Biomarcadores de Tumor/genética , Antígeno Carcinoembrionario , Proteína de la Matriz Oligomérica del Cartílago/genética , Moléculas de Adhesión Celular , Neoplasias del Colon/patología , Proteínas Ligadas a GPI/genética , Humanos , PronósticoRESUMEN
Microplastic pollution is an emerging environmental problem, and little research has focused on its impact on the human body. Based on retrospective case series, the study required participants to fill out a questionnaire and provide sputum samples in order to investigate the presence of microplastics in human sputum and determine whether humans involuntarily inhale them. A total of 22 patients suffering from different respiratory diseases were recruited. We used an Agilent 8700 laser infrared imaging spectrometer and Fourier-transform infrared microscope to analyze sputum samples and evaluate microplastics in the respiratory tract. Remarkably, the size range of the method for detecting microplastics in our study is 20-500 µm. The results showed that 21 types of microplastics were identified, and polyurethane was dominant, followed by polyester, chlorinated polyethylene, and alkyd varnish, accounting for 78.36% of the total microplastics. Most of the aspirated microplastics detected are smaller than 500 µm in size (median: 75.43 µm; interquartile range: 44.67-210.64 µm). Microplastics are ubiquitous in all sputum, indicating that inhalation is a potential way for plastics to enter the human body. Additionally, the quantities of microplastic types in the respiratory tract are related to smoking, invasive examination, etc. (P < 0.05). This study sheds new light on microplastic exposure, which provides basic data for the risk assessment of microplastics to human health.
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Microplásticos , Contaminantes Químicos del Agua , Monitoreo del Ambiente , Humanos , Plásticos/análisis , Estudios Retrospectivos , Espectroscopía Infrarroja por Transformada de Fourier , Esputo/química , Contaminantes Químicos del Agua/análisisRESUMEN
Chirality plays a pivotal role in drugs, agrochemicals and food additives et al. The enantiomers of a chiral molecule often show huge difference in bioactivity, metabolism, and toxicity et al. thereby, the recognition of chiral molecules shows an increasingly important priority. In this paper, a novel method for chiral fluorescence recognition based on anthracene fluorescent dyes (AD) â water-soluble pillar[5] arene containing phosphonic acid group (PWP[5]) is developed. The AD as guest molecule can complex with PWP [5] to form 1:1 AD â PWP[5] assembly, and this assembly can be further used as a fluorescent probe to identify D/L-phenylalanine and D/L-phenylalaninol by fluorescent titration. The fluorescence intensity of the assembly was significantly reduced for D-phenylalanine and D-phenylalaninol, while L-phenylalanine or L-phenylalaninol was added to AD â PWP[5] assembly, the fluorescence intensity of the assembly almost unchanged. Hence, the chiral recognition based on assembly between the achiral fused ring fluorescent dye and achiral PWP[5] was developed.
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Calixarenos/química , Colorantes Fluorescentes , Compuestos de Amonio Cuaternario/química , Agua , Antracenos , Fluorescencia , Colorantes Fluorescentes/química , Fenilalanina , Ácidos FosforososRESUMEN
BACKGROUND: We aimed to explore the association between long-term exposure to particulate matter ≤ 2.5 µm (PM2.5) and metabolic syndrome (MetS) and its components including fasting blood glucose (FBG), blood pressure, triglyceride (TG), high-density lipoprotein cholesterol (HDL-c) and waist circumference among adults and elderly in south China. METHODS: We surveyed 6628 participants in the chronic disease and risk factors surveillance conducted in 14 districts of Guangdong province in 2015. MetS was defined based on the recommendation by the Joint Interim Societies' criteria. We used the spatiotemporal land-use regression (LUR) model to estimate the two-year average exposure of ambient air pollutants (PM2.5, PM10, SO2, NO2, and O3) at individual levels. We recorded other covariates by using a structured questionnaire. Generalized linear mixed model was used for analysis. RESULTS: A 10-µg/m3 increase in the two-year mean PM2.5 exposure was associated with a higher risk of developing MetS [odd ratio (OR): 1.17, 95% confidence interval (CI): 1.01, 1.35], increased risk of fasting blood glucose level. (OR: 1.18, 95% CI: 1.02, 1.36), and hypertriglyceridemia (OR: 1.36, 95% CI: 1.18, 1.58) in the adjusted/unadjusted models (all P < 0.05). We found significant interaction between PM2.5 and the region, exercise on the high TG levels, and an interaction with the region, age, exercise and grain consumption on FBG (P interaction < 0.05). CONCLUSIONS: Long-term exposure to PM2.5 was associated with MetS, dyslipidemia and FBG impairment. Efforts should be made for environment improvement to reduce the burden of MetS-associated non-communicable disease.
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Contaminantes Atmosféricos , Síndrome Metabólico , Adulto , Anciano , Contaminantes Atmosféricos/efectos adversos , Glucemia/metabolismo , China/epidemiología , Humanos , Síndrome Metabólico/complicaciones , Síndrome Metabólico/epidemiología , Material Particulado/efectos adversos , TriglicéridosRESUMEN
Water pollution is an increasingly serious problem. Here, Cu and Zn ions were used as stress factors, and G. affinis served as a test organism. Fluorescence quantitative PCR was used to detect changes in the expression of antioxidant genes (SOD, GST, CAT), heat stress genes (Hsp70, Hsp90, Hspd1, Hsc70), and immune system-related genes (IL-1ß, IL-8) in G. affinis exposed to Cu and Zn ions over time. To explore the toxic effects of Cu and Zn on G. affinis. The results showed that the 48 h LC50 concentrations of the heavy metals Cu and Zn to G. affinis were 0.17 mg/L and 44.67 mg/L, respectively. Within 48 h, with prolonged Cu exposure, the relative expression levels of the Hsp70, Hsp90, Hspd1, Hsc70, SOD, GST, and CAT genes in the gill tissue first showed a significant increase and then gradually decreased. Gene expression peaked between 9 and 36 h. The relative expression levels of SOD and GST genes in liver tissue showed a gradual decline. Within 48 h, with prolonged Zn exposure, the expression levels of SOD, CAT, and GST genes in G. affinis first increased and then fell before finally rising. The expression levels of IL-1ß and IL-8 mRNA showed varying degrees of upward trends, and the expression of IL-8 was the highest for all gill tissue. To sum up, Cu and Zn have strong toxic effects on G. affinis, which makes it possible to use G. affinis as indicator organisms for aquatic environmental pollution.
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Ciprinodontiformes , Metales Pesados , Animales , Antioxidantes , Interleucina-8 , Metales Pesados/toxicidad , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/genética , Chaperonina 60 , Contaminación del Agua , Respuesta al Choque Térmico/genética , Superóxido Dismutasa/genética , Zinc/toxicidadRESUMEN
BACKGROUND: The characteristics of prostate cancer on autopsy and early-stage prostate cancer are identical. Using autopsy specimens, we analysed prostate cancer characteristics and clarified the spatial distributions of lesions. METHOD: We obtained prostate specimens from Chinese donors without a prostate cancer diagnosis and analyzed prostate cancer pathological characteristics on autopsy by whole-mount sampling. We determined the distributions of lesions in horizontal and vertical dimensions. The horizontal dimension included four horizontal quadrants (left-anterior, left-posterior, right-anterior, and right-posterior quadrants), the peripheral zone, and the transition zone. RESULT: The overall positive rate of prostate cancer among 113 specimens was 35.4%. There were 73 lesions in 40 prostates with prostate cancer. The positive rates of lesions in the left-anterior, left-posterior, right-anterior, and right-posterior quadrants were 24.7% (18/73), 27.4% (20/73), 26.0% (19/73), and 21.9% (16/73), respectively. The positive rate of prostate cancer was 74% in the areas between the apex above 0.5-0.8 cm and the middle slice. There were 22 (30.1%) and 51 (69.9%) lesions in the superior and inferior half of the prostate. There were no significant differences in the median volume and Gleason grade group between the superior and inferior half (p = .876 and p = .228). CONCLUSION: In the horizontal dimension, the positive rate of prostate cancer was consistent in the four quadrants. Prostate cancer mainly originated from the areas between the apex above 0.5-0.8 cm and the middle slice. Compared with the superior half, the inferior half of the prostate had a higher positive rate but the same lesion characteristics.
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Autopsia , Próstata/patología , Neoplasias de la Próstata/patología , Anciano , Anciano de 80 o más Años , Autopsia/métodos , Biopsia , China/epidemiología , Humanos , Masculino , Neoplasias de la Próstata/epidemiologíaRESUMEN
BACKGROUND: Selenium (Se) is a trace element that has been linked to many health conditions. Genome-wide association studies (GWAS) have identified variants for blood and toenail Se levels, but no GWAS has been conducted to date on responses to Se supplementation. OBJECTIVES: A GWAS was performed to identify the single nucleotide polymorphisms (SNPs) associated with changes in Se concentrations after 1 year of supplementation. A GWAS of basal plasma Se concentrations at study entry was conducted to evaluate whether SNPs for Se responses overlap with SNPs for basal Se levels. METHODS: A total of 428 participants aged 40-80 years of European descent from the Selenium and Celecoxib Trial (Sel/Cel Trial) who received daily supplementation with 200 µg of selenized yeast were included for the GWAS of responses to supplementation. Plasma Se concentrations were measured from blood samples collected at the time of recruitment and after 1 year of supplementation. Linear regression analyses were performed to assess the relationship between each SNP and changes in Se concentrations. We further examined whether the identified SNPs overlapped with those related to basal Se concentrations. RESULTS: No SNP was significantly associated with changes in Se concentration at a genome-wide significance level. However, rs56856693, located upstream of the NEK6, was nominally associated with changes in Se concentrations after supplementation (P = 4.41 × 10-7), as were 2 additional SNPs, rs11960388 and rs6887869, located in the dimethylglycine dehydrogenase (DMGDH)/betaine-homocysteine S-methyltransferase (BHMT) region (P = 0.01). Alleles of 2 SNPs in the DMGDH/BHMT region associated with greater increases in Se concentrations after supplementation were also strongly associated with higher basal Se concentrations (P = 8.67 × 10-8). CONCLUSIONS: This first GWAS of responses to Se supplementation in participants of European descent from the Sel/Cel Trial suggests that SNPs in the NEK6 and DMGDH/BHMT regions influence responses to supplementation.
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Suplementos Dietéticos , Estudio de Asociación del Genoma Completo , Genotipo , Selenio/sangre , Selenio/farmacología , Población Blanca , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Selenio/administración & dosificaciónRESUMEN
BACKGROUND: Due to the invasiveness of prostate biopsy, a prediction model of the individual risk of a positive biopsy result could be helpful to guide clinical decision-making. Most existing models are based on transrectal ultrasonography (TRUS)-guided biopsy. On the other hand, transperineal template-guided prostate biopsy (TTPB) has been reported to be more accurate in evaluating prostate cancer. The objective of this study is to develop a prediction model of the detection of high-grade prostate cancer (HGPC) on initial TTPB. RESULT: A total of 1352 out of 3794 (35.6%) patients were diagnosed with prostate cancer, 848 of whom had tumour with Grade Group 2-5. Age, PSA, PV, DRE and f/t PSA are independent predictors of HGPC with p < 0.001. The model showed good discrimination ability (c-index 0.886) and calibration during internal validation and good clinical performance was observed through decision curve analysis. The external validation of CPCC-RC, an existing model, demonstrated that models based on TRUS-guided biopsy may underestimate the risk of HGPC in patients who underwent TTPB. CONCLUSION: We established a prediction model which showed good discrimination ability and calibration in predicting the detection of HGPC by initial TTPB. This model can be used to aid clinical decision making for Chinese patients and other Asian populations with similar genomic backgrounds, after external validations are conducted to further confirm its clinical applicability.
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Modelos Teóricos , Neoplasias de la Próstata/patología , Anciano , Biopsia/métodos , Humanos , Masculino , Persona de Mediana Edad , Perineo , Valor Predictivo de las Pruebas , Estudios RetrospectivosRESUMEN
BACKGROUND: Abnormal semen quality is one of the common causes of infertility. The relationship between exposure to air pollutants and semen quality is unclear. OBJECTIVES: To evaluate the impact of ambient air pollutant exposures on semen quality. METHODS: We analyzed 3797 semen samples from Guangdong Human Sperm Bank between May 28, 2018 and March 31, 2019. The inverse distance weighted interpolation method was used to estimate the personal exposures to CO, SO2, NO2, O3, PM10 and PM2.5 during the entire period (0-90 lag days) and key periods (0-9, 10-14, 70-90 lag days) of sperm development. Linear mixed models were used to evaluate the exposure-response relationships between air pollutants and semen quality, including sperm concentration, sperm count and sperm motility, after adjusting for other covariates. The regression coefficients and 95% confidence intervals (CIs) associated with each interquartile range (IQR) increase in pollutant concentrations were estimated for each semen quality parameter. RESULTS: Overall, we observed a significant association of decreased sperm count with the exposure to PM10 (-0.2466; -0.4443, -0.0489) and PM2.5 (-0.2910; -0.5401, -0.0419). Among the sperm quality parameters assessed, sperm count was observed more frequently to be negatively associated with ambient air pollutants (CO, NO2, O3, PM10 and PM2.5), especially for the period during 10-14 lag days. In addition, motility decline was significantly associated with O3 in the late stage of sperm development. Sensitivity analyses for subgroup population yielded similar results. No significant association was found between all pollutants and sperm concentration (all P > 0.05). CONCLUSIONS: Our results indicate that ambient air pollutants exposures during sperm development may have an adverse effect on semen quality, especially for sperm count and motility. The findings emphasize the potential to improve semen quality by reducing ambient air pollutant exposures, and the importance of taking into account the critical period of sperm development when protective measures are implemented.
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Contaminantes Atmosféricos , Contaminación del Aire , Contaminantes Atmosféricos/análisis , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , China/epidemiología , Estudios de Cohortes , Humanos , Masculino , Material Particulado/análisis , Estudios Retrospectivos , Análisis de Semen , Motilidad Espermática , EspermatozoidesRESUMEN
In CO2 electroreduction, the critical bottleneck lies in the CO2 activation which requires high overpotentials. CO2 activation is related to both the electronic structures of catalysts and those of adsorbates, thus an ideal catalyst should match its electronic structures with those of the adsorbate. Here, we harmonized the electronic structures of the adsorbate and Mn-doped In2S3 nanosheets for efficient CO2 reduction. The introduction of Mn dopants into In2S3 nanosheets enhanced both the Faradaic efficiency (FE) for carbonaceous products and current density (j). At -0.9 V vs RHE, Mn-doped In2S3 nanosheets exhibited a remarkable FE of 92% for carbonaceous product at a high j of 20.1 mA cm-2. Mechanistic studies revealed that Mn doping enabled the harmonic overlaps between the p orbitals of O atoms and d orbitals of Mn atoms near the conduction band edge of Mn-doped In2S3 nanosheets during the activation of CO2. Due to the unique electronic structures of the coadsorbed configurations, Mn-doped In2S3 nanosheets exhibited an energy barrier for CO2 activation into HCOO* lower than that over pristine In2S3 nanosheets.
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A series of monomers containing tetraphenylsilane connected to different thiophenes such as thiophene, bithiophene and terthiophene were designed and synthesized and were further used to prepare the corresponding polymers via electrochemical polymerization (pSiTPTP, pSiTPBTP and pSiTPTTP). From the polymers, the effective conjugate elements were well defined as bithiophene, quaterthiophene and sexithiophene because the sp3 Si atom can block the conjugation between the thiophene units in the polymer backbone. The spectroelectrochemical results indicated that pSiTPTP is incapable of electrochromism, which may be attributed to the insufficient conjugation length of the independent bithiophene. In contrast, both pSiTPBTP and pSiTPTTP exhibited obvious electrochromic properties and furthermore, pSiTPTTP displayed a shorter switching time and better stability. Such different electrochemical behaviors can be ascribed to the looser stacking structure and lower oxidation potential of pSiTPTTP with the independent sexithiophene unit. The EIS measurements also confirmed the lower charge-transfer resistance and higher ion-diffusion rate of pSiTPTTP with the independent sexithiophene unit. Hence, we can conclude that the effects of the electrochromic behavior of the conjugation-broken polythiophene derivatives depend on the increased conjugation length of the thiophene repeating unit, in which the inadequate electrochromism with bithiophene units can change to superior electrochromic properties with increased sexithiophene units.
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Charge doping is an effective way to induce the metal-insulator transition (MIT) in correlated materials for many important utilizations, which is however practically limited by problem of low stability. An electron-proton co-doping mechanism is used to achieve pronounced phase modulation of monoclinic vanadium dioxide (VO2 ) at room temperature. Using l-ascorbic acid (AA) solution to treat VO2 , the ionized AA- species donate electrons to the adsorbed VO2 surface. Charges then electrostatically attract surrounding protons to penetrate, and eventually results in stable hydrogen-doped metallic VO2 . The variations of electronic structures, especially the electron occupancy of Vâ 3d/Oâ 2p hybrid orbitals, were examined by synchrotron characterizations and first-principle theoretical simulations. The adsorbed molecules protect hydrogen dopants from escaping out of lattice and thereby stabilize the metallic phase for VO2 .